1. Field of the Invention
This invention relates, in a broad sense, to an attitude control device for a transportation vehicle, such as an air craft or the like, and more particularly to an attitude control device for an air or sea transportation vehicle, such as an air craft or the like, in which a servo-motor and a fluid pressure pump are used and controlled electronically.
Specifically, a first aspect of the invention relates to an attitude control device adapted to control the flaps of an air craft, a second aspect of the invention relates to an attitude control device adapted to control a link mechanism of a rotor of a helicopter, and a third aspect of the invention relates to an attitude control device adapted to control a rudder of a marine vessel.
2. Brief Description of the Prior Art
In order to control pitch, yaw, roll, etc. using rudder, elevator, aileron, etc., a wire is used in small air crafts, but a hydraulic system is employed for all large air crafts. At present, as the supersonic air craft appears in use, control circuitry having a very quick response is required. To this end, a hydraulic control system using a servo valve occupies the main stream usage.
Such an actuator control system using the servo valve is extremely inefficient, i.e. about 15.about.30% efficient. For an air craft, efforts have been successful for reducing the body weight and for improving the engine efficiency. However, regarding attitude control, it seems that since the advantages of the fluid pressure system are so valuable and the response of the servo valve is so excellent, the bad efficiency is disregarded. Also, in the conventional device, fluid pipings are disposed throughout the air craft, which is far from a fuel safe concept.
As seen from the perspective view of an air craft of FIG. 2, distributed control is performed by providing an actuator for each flap. Even if the fluid piping is dispersed in the best possible manner, there still remains a disadvantage in that the entire hydraulic pressure of the particular system is lowered when one piping is cut, as long as the pump system is collectively arranged as one group. In fact, a large passenger air craft was recently disabled due to a lowered hydraulic pressure caused by a breakage of the fluid piping of the control system, which in turn was caused by the destruction of the pressure partition.